Apparatus and process for relieving pain and discomfort



A. Z. WEISZ July 14, 1964 APPARATUS AND PROCESS FOR RELIEVING PAIN ANDDISCOMFORT Filed May 29, 1961 2 Sheets-Sheet 1 F195 Ema:

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0 2'3 ALEXA/V05? z Wf/JZ D 2? BY United States Patent 3 140,709APPARATUS AND RROCESS FOR RELIEVING PAIN AND DISCOMFORT Alexander Z.Weisz, Belmont, Mass, assignor to Bolt Beranelr and Newman Inc.,Cambridge, Mass., :1 corporation of Massachusetts Filed May 29, 1961,Ser. No. 113,476 11 Claims. (Cl. 128--1) The present invention relatesto apparatus and processes for relieving a patients pain and discomfortwith the aid of acoustic energy.

In copending Application Serial No. 779,365 of Wallace 1. Gardner andJoseph C. R. Licklider, filed December 10, 1958, now Patent No.2,986,140 for apparatus and process for relieving pain and discomfort,there are disclosed techniques and apparatus for alleviating a patientssensation of pain and discomfort by flooding the auditory system of thepatient with appropriate acoustic energy. This invention has gone intowide use and has proved to be highly successful. In order to protect thehearing of the patient, it has become standard procedure in theutilization of the audio analgesic treatments employing theabove-mentioned techniques and apparatus, to limit the length ofuninterrupted exposure of the patient to the audio energy tosubstantially minutes at the highest intensity settings of theapparatus. While it is possible to increase the allowable exposure timeby reducing the acoustic energy intensities offered to the patientsauditory system, the intensity of the pain and discomfort that may bealleviated becomes thereby decreased.

An object of the present invention, accordingly, is to provide a new andimproved process and apparatus for relieving a patients sensation ofpain and discomfort through the employment of appropriate acousticenergy that shall extend the permissible exposure time of the patient toacoustic energy of intensities sufiicient to alleviate severe pain,without exceeding the above-mentioned established maximum allowableexposure.

A further object is to provide a new and improved audio energy analgesicapparatus.

Other and further objects will be explained hereinafter and will be moreparticularly pointed out in connection with the appended claims.

In summary, the invention relates to the obviating of a patientsreaction to pain and discomfort by alternating the application of theappropriate acoustic energy between opposite sides of the patientsauditory system.

The invention will now be described in connection with the accompanyingdrawings, FIG. 1 of which is a combined block and schematic circuitdiagram illustrating the invention in preferred form; and

FIG. 2 is a similar view of a modification.

Referring to FIG. 1, audible sound signals, preferably substantiallycontinuous in frequency spectrum and time, are generated by the sources1 and 1 which may respectively be sources of intelligible sound signalssuch as music and the like and of noise signals and the like. As isexplained in the said copending application, such sound signals areapplied to the auditory system of the patient during the subjection ofthe patient to a painor discomfort-producing stimulus, with amplitudelevel controls provided as at 2 and 2' for enabling the patientrelatively to increase the amplitude level of the noise and musicsignals at least to a level substantially 100 decibels above .0002 ubalfor a period at least substantially commensurate with the duration ofthe stimulus, whereby said sensation of pain or discomfort resultingfrom said stimulus is relieved. In the system of FIG. 1, the music isshown applied, preferably stereophonically, through left and rightamplifier channels 4 and 6, respectively, and through resistors R1 andR2 and conductors 3 and 5 to 3,140,709 Patented July 14, 1964 the leftand right sound-reproducing earphones 4' and 6', which are peripherallyprovided with flanges, shown in heavy lines at F, that mask other soundsfrom being injected through the ears into the auditory system.

The output of the noise source 1', which may, for example, be a thermalgas tube, as is well known, is shown fed through a pair ofphoto-resistors R and R and respective resistances R3 and R4 to therespective conductors 3 and 5 that feed the sound-reproducing earphonesor other sound-injecting devices 4 and 6. The photo resistors are alsoconnected to appropriate ground cir cuits through respective resistancesR5 and R6. A motordriven cam 7 is shown operating upon a pivoted switchS to cause the switch to alternately connect with upper and lowercontact members 9 and 11. They, in turn, connect with the filaments Fand F of respective light sources L and L disposed to illuminate,respectively, the photo-resistors R and R. The switch S is electricallyconnected through a variable resistor R9 to the ground or other terminaland, depending upon whether the switch S contacts the contactor 9 or 11through the respective resistors R7 and R8, to a source S of voltage,such as the alternating current mains. As the motor-driven cam 7rotates, the lamps L and L will become alternately illuminated,alternately raising and lowering the resistance of the photo-resistors Rand R and thus causing the noise signal alternately to be fed to theleft and right earphones or similar devices 4 and 6', during thecontinual background feeding of the music thereto.

This alternate or intermittent application of the noise sound (which isgenerally most effective in reducing the sensation of pain anddiscomfort) to opposite sides of the patients auditory system, enablesthe taking advantage of a significant reduction in the growth oftemporary threshold shift in each ear, for example, during suchalternate or intermittent exposure. In fact, at the same intensities oramplitude levels which conventionally allow a 15 minute exposure, thepresent invention enables the patient safely to tolerate a total of 135minutes exposure to the audio energy by the alternation of the samebetween opposite sides of the auditory system of the patient. Sincesound pressure levels of about db or less do not contribute to temporarythreshold shifts, it is not necessary to shut the sound off completelyfrom the side of the auditory system to which the noise source is notbeing fed. The music, therefore, may remain on continuously while themasking noise sound is alternated between op posite sides of theauditory system. It has been found that the patient is able to followthe music with intelligibility under such conditions despite the highmasking noise levels to which the patient adjusts the output of thesource 1' to obtain relief from the pain.

Other advantages accruing to the present invention reside in the factthat the sound has a spatial and temporal dimension that adds to thedesirable effects of distraction and diversion, with certain naturalrhythms, such as those of waves washing ashore or breathing, simulatedby the alternating mechanism with further beneficial effects. Inaddition, since the analgesic eifect is to some extent proportional tothe sound pressure level applied to the ear, the present inventionpermits, for equivalent temporary threshold shifts, the attenuation ofhigher intensities of pain; though, of course, the time of exposure tothe audio energy must be sacrificed for such higher levels. A convenientalternating rhythm or frequency successfully employed has been onceevery four seconds, with some over lap or decay during the change-over,which has been found to be pleasing to the patient.

In the modification of FIG. 2, the output of the noise source 1 isalternated by a motor-driven rheostat, shown in circular form at RHprovided with diametrically opposed conductive sliders S1 and S2respectively insulated from and electrically connected to the shaft 13of the motor M, but both rotated therewith.- Brushes 15 and 17respectively engaging a conductive cylinder 19 connected to the sliderS1 and the shaft 13, will thus alternately feed'incr'easing anddecreasing levels of noise to amplifiers'No. 1 and No.'2, alternately toenergize the sound reproducing members 4 and 6.

Further modifications will occur to those skilled in the art, and allsuch are considered to fall within the spirit and scope of the inventionas defined in the appended claims.

What is claimed is:

1. A' process for obviating a patients reaction of pain and discomforttoa painor discomfort-producing stimulus, that comprises, producingacoustic energy including noise-like sound signals of amplitude leveladjustable at least to substantially 100 decibels above 0.0002 microbar,applying the energy to the auditory system of the patient during theapplication of said stimulus, adjusting the level of the acoustic energyto a value at which the patients said reaction is substantiallyobviated, and alternating the application of the energy between oppositesides of the said auditory system.

2. A process for obviating a patients reaction of pain and discomfort toa pain-or-discomfort-producing stimulus, that comprises, producingacoustic energy comprising noise of amplitude level adjustable at leastto substantially 100 decibels above 0.0002 microbar, applying the energyto the auditory system of the patient during the application of the saidstimulus, adjusting the level of the acoustic energy to a value at whichthe patients said reaction is substantially obviated, and alternatingthe application of the energy between opposite sides of the saidauditory system.

3. A process for obviating a patients reaction of pain and discomfort toa painor discomfort-producing stimulus, that comprises, producingacoustic energy comprising an intelligible signal such as music and thelike and a noise-like signal of amplitude level adjustable at least tosubstantially 100 decibels above 0.0002 microbar, applying the energy tothe auditory system of the patient during the application of the saidstimulus, adjusting the level of the noise-likesignal relative to theintelligible signal to a value at which the patients said reaction issubstantially obviated, and alternating the application of thenoise-like'signal between opposite sides of the said auditory system.

4. A process as claimed in claim 1 and in which the alternating iseffected by gradually reducing the level of the "energy applied to oneside of the said auditory system while gradually increasing the level ofthe energy applied to the other side.

5. A process as claimed in claim 1 and in which the alternating iseffected at a predetermined rhythm.

6. A process as claimed in claim 5 and in which the rhythm is of theorder of once every few seconds.

7. Apparatus of the character described comprising a source ofelectrical signals corresponding to noise-like sound energy of amplitudelevel adjustable at least to substantially decibels above 0.0002microbar, a pair of sound-reproducing means connected to the source toreproduce noise sound energy from the said signals, and means interposedin the connection between the source and the sound-reproducing means forcyclically substantially simultaneously varying in respectively oppositedirections, the level of the electrical signals fed to each of therespective sound-reproducing means of the said pair of sound-reproducingmeans in order to increase the sound volume in one sound-reproducingmeans while decreasing the volume in the other. I

8. Apparatus of the character described comprising source means ofelectrical signals corresponding to intelligible sound energy, such asmusic and the like, and noise-like sound energy of amplitude leveladjustable at least to substantially 100 decibels above 0.0002 microbar,a pair of sound-reproducing means connected to the source means toreproduce sound energy from the said signals, and means interposed in aconnection between the source means and the sound-reproducing means forcyclically substantially simultaneously varying, in respectivelyopposite directions, the level of the electrical signals correspondingto noise-like sound energy fed to each of the respective soundreproducing means of the said pair of sound-reproducing means in orderto increase the sound volume in the sound-reproducing means whiledecreasing the volume in the other, while continually applying theelectrical signals corresponding to the intelligible sound energy to thesound-reproducing means.

9. Apparatus as claimed in claim 8 and in which the said source meanscomprises a source of electrical signals corresponding. to music and thelike permanently connected to the sound-reproducing means and a separatesource of electrical signals corresponding to noise-like sound energyconnected through the said interposed alternately-varying-level means.

10. Apparatus as claimed in claim 7 and in which thealternate]y-varying-level means comprises photo-sensitive variableimpedance means.

11. Apparatus as claimed in claim 7 and in which thealternately-varying-level means comprises rheostat means provided withsimultaneous increasing and decreasing resistance controls.

References Cited in the file of this patent UNITED STATES PATENTS2,114,019 Friebus Apr. 12, 1938 2,373,560 Hanert Apr. 10, 1945 2,986,140Gardner et al May 30, 1961

1. A PROCESS FOR OBVIATING A PATIENT''S REACTION OF PAIN AND DISCOMFORTTO A PAIN- OR DISCOMFORT-PRODUCING STIMULUS, THAT COMPRISES, PRODUCINGACOUSTIC ENERGY INCLUDING NOISE-LIKE SOUND SIGNALS OF AMPLITUDE LEVELADJUSTABLE AT LEAST TO SUBSTANTIALLY 100 DECIBELS ABOVE 0.0002 MICROBAR,APPLYING THE ENERGY TO THE AUDITORY SYSTEM OF THE PATIENT DURING THEAPPLICATION OF SAID STIMULUS, ADJUSTING THE LEVEL OF THE ACOUSTIC ENERGYTO A VALUE AT WHICH THE PATIENT''S SAID REACTION IS SUBSTANTIALLYOBVIATED, AND ALTERNATING THE APPLICATION OF THE ENERGY BETWEEN OPPOSITESIDES OF THE SAID AUDITORY SYSTEM.